Helically wound laminated bearings and method of manufacture

ABSTRACT

An improved cylindrical bearing material of a laminated construction employs a plurality of alternating cylinderical shells of elastomer and metal laminated together in which each metal shell is formed by helically winding a band of the metal in an edge-wise, abutting relationship to form a cylindrical metal shell or sleeve. The resulting bearing material, composed of a plurality of alternating concentric elastomeric and metallic shells can be confined between a cylindrical core and an outer cylindrical retaining ring to form a bearing assembly in which the bearing material may be placed under a radial pre-load, if desired, to decrease its radial deflection when it is placed under radial loads. In the preferred embodiment of the invention, the adjacent metal shells are wound in opposite directions to stabilize the bearing material under torsional loading.

United States Patent Brandon et al.

[54] HELICALLY WOUND LAMINATED BEARINGS AND METHOD OF MANUFACTURE [72]Inventors: William D. Brandon; Jack A. Drais, both of Peoria, Ill. [73]Assignee: Caterpillar Tractor Co., Peoria,

Ill.

[22] Filed: Oct. 5, 1970 [211 App]. No.: 77,819

[52] U.S. Cl. ..267/57.l [51] Int. Cl. ..Fl6c l/l0 [58] Field of Search..267/57. 1; 156/184 [56] References Cited UNITED STATES PATENTS3,504,902 4/1970 Irwin ..267/57.1 3,083,065 3/1963 l-Iinks et al..267/57.l

[15] 3,690,639 51 Sept. 12, 1972 Primary Examiner-James B. MarbertAttorney-Fryer, Tjensvold, Feix, Phillips & Lempio [5 7] ABSTRACTbetween a cylindrical core and an outer cylindrical retaining ring toform a bearing assembly in which the bearing material may be placedunder a radial preload, if desired, to decrease its radial deflectionwhen it is placed under radial loads. In the preferred embodiment of theinvention, the adjacent metal shells are wound in opposite directions tostabilize the bearing material under torsional loading.

17 Claims, 10 Drawing Figures P'ATENTEDsEP 12 m2 SHEET 1 0F 3 INVENTORSWILLIAM D. BRANDON JACK A. DRAIS PRIOR ART P I JXT'IISRNEYS PATENTED3.690.639

SHEET 2 0F 3 INVENTORS LIAM D. BRANDON A K A. DRAIS BY f PATENTEDSEPIZIW3.690.639

SHEET 3 BF 3 I I'NVENTORS WILLIAM D. BRANDON JACK A. DRAIS W W: f

HELICALLY WOUND LAMINATED BEARINGS AND METHOD OF MANUFACTURE BACKGROUNDOF THE INVENTION In particular, the instant invention is related tobearings employing alternate layers of metal and el'astomers to formlaminated bearing structures, as disclosed in US. Pat. No. 3,071,422issued to Hinks. In these laminated bearing structures, the layers ofthe bearings are kept relatively thin with the thickness of theelastomer layer being usually under 0.05 inch in thickness to limitbearing deflection when a force is applied normal to the elastomerlayers.

Fabrication of bearings of this type is usually accomplished byemploying a continuous metallic strip preferably coated with elastomerson one or more sides or faces, which is wound spirally about an axis ofrevolution to form -a bearing laminate wherein the metal layer isseparated by an elastomer layer, thereby forming a spiral laminatedstructure. While it is not necessary to apply the elastomer layer to themetal layer before it is wound, it is usually more convenient since theelastomer can be sprayed, painted or otherwise deposited on one or morefaces of the metallic strip employed to form the bearing.

Bearings constructed according to the above teachings have been quitesatisfactory in a number of applications. However, when bearings of thistype are subjected to high radial loading and torsional loadings, theadjacent metal layers shift, placing elastomer layers under tension aswell as causing deflection, thereby limiting the performance and servicelife of such bearings due to the deterioration of the elastomer layers.

The prior art bearings of this type fabricated for radial loadingapplications are typically represented by the structure shown in FIG. 1of the above-referenced Hinks patent wherein the metallic strip coatedwith elastomer is wound in a superimposed spiral on a core to formabearing laminate.

In such a bearing structure formed of an uninterrupted spiral, torsionalloading would cause the bearing to materially stiffen in one torsionaldirection and lessen in the opposite torsional direction developing highlocalized stresses. In both situations the metal layer tends either towind up the spiral or unwind the spiral causing a shifting in the metallayers of the bearing structure, placing the elastomer layers undertension and subjecting them to damage. US. Pat. No. 3,235,941, issued toKrotz, recognized this characteristic, and in order to avoid theresulting problems in differential tensional stiffness found in thespirally wound laminate bearings, employed a plurality of notches in themetal strip forming the spiral in order to form a plurality ofindividual connected plates" through the interruptions caused by thenotches thereby achieving the same stiffness to torsional loading inboth directions. Krotz indicated that an alternative of a large numberof concentric sleeves of metal and elastomer in such a hearing would bedifficult, if not impossible, to manufacture.

One of the problems of employing the concept set forth in the Krotzpatent is that the large number of sharp edges which are formed aboutthe notches tend to cut or chew" the elastomer as the bearing isdeflected torsionally under radial loading thereby seriously limitingthe service life of the elastomer. Since the elastomer is substantiallyincompressible, if flows" into the notches under radial loadings(compression) where the edges chew" the elastomer causing progressivedeterioration. In US. Pat. No. 3,377,110, a preloaded laminated radialbearing structure is disclosed employing segments or stacks formed oflaminated bearing material in order to avoid some of the problemsexperienced with the continuous spiral wound bearings disclosed in theabove-referenced Hinks and Krotz patents. However, due to the limitednumber of segments which can be employed in the bearing design, it hasonly a limited radial load capacity. Further, the large number of edgesof the metal layers in each stack tend to cut and damage the elastomerif the bearing is torsionally deflected under radial loading therebylimiting its service life. Due to the void areas in the abovereferencedtypes of bearings having uniform torsional stiffness, it is desirable tocarefully locate and orient the bearings so that the highest radialloads did not occur in the area of slots or openings, representing thelowest bearing strength where loading often tends to increase abruptchanges in the contour of or causes diametral ridges in the metal layerswhich can result in stress I risers and consequently premature: failureof the bearing material.

It is an object of the instant invention to overcome a the aboveproblems in laminate bearings designed for high radial loadingapplications. by a new fabrication for a laminated cylindrical bearingmaterial wherein the alternate layers of elastomer and metal are formedof concentric cylindrical shells which will allow torsional loadings tobe distributed uniformly throughout the bearing material when it isunder high radial loadings without damage to the elastomer layersthereby providing exceptional service life.

SUMMARY OF THE INVENTION The instant invention accomplishes the aboveprincipal object with a cylindrical laminated bearing material includinga plurality of concentric alternate sleeves or shells of metal andelastomer with each of said metal sleeves or shells formed by helicallywinding a strip or band of metal about a constant diameter in anedged-abutting relationship to form each metallic sleeve or shell with athin layer or shell of elastomer disposed between each adjacent metalsleeve or shell. Generally, the cylindrical laminated bearing materialis built on a mandrel by successively superimposing on its innermostsleeve or shell a plurality of subsequent alternating sleeves or shellsof elastomer and metal with each metal shell formed by winding a band ofmetallic material in an edge-abutting relationship about a substantiallyconstant diameter over a prior shell. The metal band which is helicallywound in an edgeabutting relationship may be coated with elastomer toform the intermediate elastomer shell between adjacent metal shells asthe metallic shell is formed, if desired. Also, it is preferable toalternate the direction of winding when metal shells are formed bywinding the metal band in an opposite direction whereby the seams inadjacent metallic shells will be angularly disposed relative to theseams in the adjacent shells.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more easilyunderstood from a detailed description of the preferred embodiment takenin conjunction with the attached drawings wherein:

FIG. 1 is a perspective of a typical prior art laminated bearingdesigned for radial loads;

FIG. 2 is a perspective of a cylindrical bearing structure formed withthe new bearing material according to this invention;

FIG. 3 is a radial section of the bearing structure illustrated in FIG.2;

FIG. 4 is a side elevation of the bearing structure shown in FIG. 1 withparts broken away to show additional detail of its multiple alternatingshells of metal and elastomer;

FIG. 5 is an exploded perspective of a bearing assembly employing thenovel laminated cylindrical bearing material, illustrating theconstruction of one of the metallic bearing shells or sleeves;

FIG. 6 is a perspective of the application of a metallic band by ahelically winding operation, illustrating one method of its manufactureon a powered rotating mandrel;

FIG. 7 is a perspective of simple dies employed to put a curl.in themetal band as it is wound into a metallic shell;

FIG. 8 illustrates the curl in perspective of a metallic band passedthrough the dies shown in FIG. 7;

FIG. 9 is a perspective of a typical winding machine which can beemployed to manufacture the novel bearing material; and

FIG. 10 is an elevation of a bearing structure having end-loadedelastomer washers.

BACKGROUND OF THE INVENTION While laminated bearings of the typedisclosed in the referenced prior art patents generally allow asignificant reduction in both size and weight in a given applicationover their contemporary elastomer counterparts, they have beenunsuitable in certain applications. With no metal-to-metal slidingsurfaces, they do eliminate wearing, galling and fretting without anyrequirement for lubrication as does the current invention. Also, theyeliminate the break out forces normally found in more conventionalbearings. Since both initial costs and maintenance costs of theselaminated bearings are low, they are attractive for applications whichare compatible with their characteristics and capabilities.

In the past, as noted above, the characteristics and capabilities of theprior art laminated bearings have not been satisfactory for applicationsin which high radial loadings are involved which are accompanied bytorsional deflections between articulated parts; for example, bearingsbetween connected track links on tracktype vehicles. The currentinvention is designed to provi dea laminated cylindrical bearingmaterial having the capabilities for such applications involving highradial loadings, coupled with torsional deflections.

A typical prior art bearing of a laminated construction designed forradial loadings is illustrated in FIG. 1 with arrow A representingradial loadings and arrow B representing torsional loadings on thespirally wound laminated bearing. In contrast, the construction of thecylindrical bearing material 10 of the current invention is illustratedin FIGS. 2, 3, 4, 5, and 6, and differs appreciably in design. andconstruction from the prior art bearing in that concentric andalternating cylindrical shells of elastomer and metal form the circularbearing material.

In FIGS. 2, 3, 4, and 5, the bearing material 10 is illustratedassembled in a bearing structure 11 which confines it between an innercircular core 12 and an outer retaining sleeve 13, the latter of whichmay be segmented, as illustrated in FIG. 5. The functions of the innercore and the retaining sleeve are normally to provide convenientassemblies for mounting the new bearing material in its various bearingapplications. Thus, it is apparent that these functions could also beprovided, in some situations, by appropriate structures on or in themachine itself, thereby eliminating the necessity of core and retainingsleeve.

In some situations where high radial loading will be experienced andlimited radial deflection in the bearing material is desired, theretaining sleeve 13 (the unsegmented types) can be swaged or the innercore 12 ballized to place the bearing material under a radial preload,thereby reducing-radial deflections, i.e., increasing radial stiffness.In the case of a segmented retaining sleeve, as illustrated in FIG. 5,the mating bearing support structures can be employed to squeeze" theretaining sleeve to a smaller diameter (closing the gaps 13a) to apply aradial pre-load when the bearing structure is installed in a machineapplication.

The actual configuration of the new bearing material is best shown inFIGS. 3, 4, and 5 wherein the wall thicknesses of the several shells aregreatly exaggerated solely for the purposes of illustration, since wallthickness of the metallic shells 14 may be in the order of 0.0015 to0.020 inches and the wall thickness of the elastomer shells 15 may be inthe order of 0.005 to 0.060 inches.

The alternating shells l4 and 15 of elastomer and metal, respectively,are formed usually by building the bearing material 10 on a mandrel,laying up a first cylindrical shell on a mandrel or core 12 andsubsequently laying up each successive shell on an immediate prior shelluntil the desired thickness of hearing material is achieved. Eachmetallic shell 14 is applied separately over an immediate prior shell,and a number of metallic shells can be, applied simultaneously bywrapping a second metallic shell over one just completed with anintermediate elastomer shell therebetween. A machine arrangement similarto one illustrated in US. Pat. No. 3,128,216 issued to Reed can beemployed to fabricate the bearing material 10. Employing such a machine,an axially continuous length of bearing material can be formed (lengthsof 20 to 40 feet) which then can be cut radially into selected shorterlengths.

In FIG. 9, a perspective of a wrapping machine 20 is illustrated inwhich a non-rotating mandrel 21 is axially advanced through apertures 22of the several rotating winding decks 23, each of which contains spoolswound with a metallic band 16, preferably a shim stock of thethicknesses indicated above, which may be brass-plated for improvedadhesion. The axial advance of the mandrel is timed so the metallicbands 16 are helically a wound in a substantially edgeabuttingrelationship making a tight abutting seam 17 between the convolutions ofthe helix forming each metallic shell of the cylindrical bearingmaterial,

, In FIGS. 5 and 6, an important feature of the application ofthemetallicband 16 to a prior shell (elastomer shell is illustrated. Eachmetallic band 16 is helically wound in tight edge-abutting relationshipabout a constant diameter and under tension, so the seams 17 will have aminimum gap and form asubstantially continuous cylinder. a

It should not be inferred from the above discussion that an elastomershell 15 cannot be formed simultaneously with the metallic shell, aswould be i the case where the metallic band is coated with an elastomeron one or more of its faces before it is helically wound on the mandrelor a prior shell; Also, it should be ap preciated that each subsequentvmetallic j band is preferably wound in the opposite direction (seearrows on the winding decks23 in FIG. 9), often referredto as oppositehand, so the seams 17 of the adjacent metallic shells 14 areangularly'disposed relativeto the seams in the referenced metallicshell.i The alternation of the direction of warp, between adjacent shells isvery important when the cylindrical bearing material 10 is placed undertorsionalloadings since ,it' makes the torsion stiffness uniform ineither direction. The characteristic is obtained because adjacenthelically wound metallic shells l4 tend to oppose one anotherundertorsional loadings, one tending to wind-up, the other tending tounwind, dependingon the direction of torsional deflection therebyproviding the same compensation and torsional stiffness in eitherdirection. This feature tends to maintain the elastomer shells undercompression by limiting relative movement between the metallic shellsand also helps avoid the highly localized shear forces developed inspirally wrapped prior art hearings. in addition, the metallic shellscan lengthen orshorten axially to accommodate changes in the shelldiameter duringtorsionaldeflections. I

Another-very important feature is achieved by the instant fabricationthrough a unitized bearing material in which flow of the elastomer isrestricted when the bearing material 10 is placed under load, therebylimiting the deterioration of the elastomer caused by its working acrossa plurality of edges of the metallic portions of the laminate. Sinceelastomers are substantially incompressible, they tend to flow whenplaced under compressive loading (radial loading in the case of the alsoallows the use of somewhat thicker elastomer shells. whereby decreasedtorsional stiffness can be achieved without appreciable loss of radiaistiffness.

A technique to enhance the integrity of the bearing material It) whennot confined between an outer retaining sleeve 13 and an inner core 12is to place a curl in the metallic band 16as it is being wound using asimple sharp edge die 30 as illustrated in FIG. 7. A

guide 31 back bends the metallic band so it is drawn across the edge 32of the die inits travel toward the mandrel when winding on the priorshell. As a result of this action, a curl, as illustrated. in FIG. 8,can be introduced into the band. By controlling the tension on the bandand spacing between the die and guide the diameter D, of the curl" inafree statecan be obtained which is less than the diameter D of thecylindrical metallic shell formed from the band. This curl tends toprevent unraveling of the outer metallic shells of the bearing material.Also, when the bearing material is layed-up on a machine, its endsshould be clamped" to maintain the tightness of the wrap as eachmetallicsleeve is completed.

-The elastomer employed in thefabrication can be selected from rubbers,natural, synthetic, silicone, viton, etc., which can be compounded fordesired elastomeric properties such as hardness, modulus, set,hysteresis set, resiliancy, thermal stability, etc. Also, since themetallicshells can be wound under considerable tension, some of.thelundesirable characteristics, such as elastomer relaxation? can becompensated for during fabricatiomln addition, it allows the use ofelastomers which are cured, uncured, bonded or unbonded to the metallicshells in final bearing material,

increasing the flexibility in achieving the desired parameters.

Normally, the metallic shells 14 will be formed of shim stock, thoughthe use of non-metallic material is possible if it maintains thenecessaryeffective shape factor and has the other properties required.

Since there'are no essential breaks or gaps in the concentric shellsforming the laminate of this new bearing material 10, exceptat its ends,the radial andtorsional stiffnesses are uniforrn'through 360 so nospecial bearing orientation with reference to the applied load isnecessary. Also, since the material is unitized, it can accept greaterconical loadings than other similar types of laminated bearings, thoughsuch edge-loading isundesirable. I 3

In FIG. 10, the bearing structure 11 is shown equipped with washerlayers 40 disposed normal to the concentric shells at each end of thebearing material 10. These thin washer layers are retained tightlyagainst their respective ends of the bearing material 10 by washers 41which are secured to the core member 12 usually by a press-fit.Generally, it is desirable that the washer layers be placed underpre-load to prevent the extrusion of elastomer from between the adjacentmetallic shells when the bearing is placed under high radial loads,

As can be seen in FIG. 10, the washers 41 do not extend to the outersleeve 13, but leave an annular gap 41a which should be larger than themaximum radial deflection of the bearing material. Also, the outer ends42 of the retaining sleeve 13 can be crimped, as illustrated in FIG. 10,to overlap the washers. This tends to keep dirt out of the bearing andalso forms a "stop," limiting axial deflections across the bearingmaterial which has little resistance to axial loadings.

The precompression of the bearing material during manufacture ultimatelywill depend on the ratio of the moduli of elasticity of the metal andelastomer forming desired thickness, and initial bearing loads can bedetermined by the of the cylindrical bearing can be maintained within afew thousandths even though there is some relaxation when the bearingmaterial is removed from the winding machine.

Often it is desirable to use fiat stock to form the outer retainingsleeve 13 by forming it in segments, as shown in FIG. 5, and employingthe attaching assemblies to provide the preload as previously described.

Subsequent to the build-up of the concentric shells described above, theelastomers can be cured and normally will bond to the shim stock formingthe metallic shells. However, it is not always imperative that theelastomer be bonded to the metallic shells.

After curing, the elastomer shells tend to be relieved of internalstresses and precompression if the cylindrical bearing material can beaccomplished as previously described.

A cylindrical bearing was fabricated having approximately a 3 k inchdiameter with six shells of rubber each having a wall thickness of 0.036inch with five metallic shells disposed between the rubber shells havinga wall thickness of 0.010 inch and cured. Thereafter, the bearingmaterial was preloaded by ballizing the inner core to give from to 16percent precompression of the material. This bearing was mounted in atest assembly where it underwent 1,000,000 impulse cycles of a100,000-lb. radial load,

and 1,700,000 flex cycles from :1" to :5, without failure. Radialdeflection was 0.004 inch nominal and 0.007 inch maximum.

We claim:

l. A cylindrical laminated bearing material suitable for radial andtorsional loadings comprising a plurality of alternating concentricelastomer and non-elastomer cylindrical bearing shells, eachnon-elastomer bearing shell having a continuous non-elastomer flat banddisposed in circular convolutions having substantially helicaledge-abutting relationships along a cylindrical axis to form acylindrical bearing shell with a substantially constant diameter, andsaid elastomer and nonelastomer cylindrical bearing shells beingsuccessively superimposed on the innermost shell to form a cylindricallaminate with a plurality of concentric shells.

2. The cylindrical laminated bearing material as defined in claim 1wherein an elastomer cylindrical bearing shell is disposed betweenadjacent nonelastomer cylindrical bearing shells whereby concentricnon-elastomer cylindrical bearing shells are separated in thecylindrical laminate by elastomer cylindrical bearing shells.

3. The cylindrical laminated bearing material as defined in claim 2wherein each elastomer cylindrical bearing shell is bonded to thecontiguous nonelastomer cylindrical bearing shells.

4. The cylindrical laminated bearing material as defined in claim 1wherein the non-elastomer flat band is a metal band.

5. The cylindrical laminated bearing material as defined in claim 4wherein the metal band is a brassplated steel shim stock having athickness from 0.020 to 0.0015 inches.

6. The cylindrical laminated bearing material as defined in claim 4wherein the elastomer is a rubber compounded for the esiredcharagteristics.

7. The cylindrica laminated earing material as defined in claim 5wherein each elastomer cylindrical bearing shell has a wall thicknessfrom 0.005 to 0.060 inches.

8. The cylindrical laminated bearing material as defined in claim 2wherein each elastomer cylindrical bearing shell is applied in anuncured state and is cured and bonded to its contiguous non-elastomercylindrical bearing shells.

9. The cylindrical laminated bearing material as defined in claim 2wherein the non-elastomer band in each successive non-elastomercylindrical bearing shell is disposed at an angle to the non-elastomerband in the immediately preceding non-elastomer cylindrical bearingshell whereby substantially uniform bi-directional torsional response isobtained.

10. The cylindrical laminated bearing material as defined in claim 9wherein the non-elastomer bands in adjacent non-elastomer cylindricalbearing shells are helically disposed at equal but opposite angles withreference to the axis of the cylindrical laminate.

11. A laminated bearing for radial and limited torsional loadingscomprising a core having a cylindrical outer surface, and a plurality ofconcentric elastomer and metallic cylindrical bearing shellssuccessively superimposed on said core to form acylindrical layeredlaminate thereon, each metallic cylindrical bearing shell formed by ametal band helically disposed in an edge-abutting relationship to form ametallic cylinder with a helical seam which has a substantially constantdiameter.

12. The bearing as defined in claim 11 wherein the bearing includes anouter cylindrical retaining member which is contiguously disposed on theoutermost cylindrical bearing shell of the cylindrical laminate.

13. The bearing as defined in claim 11 wherein the adjacent metalliccylindrical bearing shells forming the cylindrical laminate areseparated by elastomer cylindrical bearing shells.

14. The bearing as defined in claim 12 wherein the plurality ofconcentric elastomer and metallic cylindrical bearing shells arecompressed between the outer retaining member and the outer cylindricalsurface of the core to decrease its radial deflection in the resultingbearing.

15. The bearing as defined in claim 12 wherein the outer retainingmember is segmented with gaps between the ends of its segments wherebythe cylindrical laminate between the core and said outer retainingmember can be compressed by closing such gaps when the bearing isinstalled in cooperating structures to decrease radial deflection in theinstalled bearing.

16. The bearing as defined in claim 13 wherein the elastomer cylindricalshells are cured and bonded to their contiguous metallic cylindricalbearing shells.

17. The bearing as defined in claim 11 wherein the metal bands formingthe metallic cylindrical bearing shells are cold-worked to induce a curlin said metal bands. approximately the diameter of the cylindricallaminate when they are wound.

2. The cylindrical laminated bearing material as defined in claim 1wherein an elastomer cylindrical bearing shell is disposed betweenadjacent non-elastomer cylindrical bearing shells whereby concentricnon-elastomer cylindrical bearing shells are separated in thecylindrical laminate by elastomer cylindrical bearing shells.
 3. Thecylindrical laminated bearing material as defined in claim 2 whereineach elastomer cylindrical bearing sHell is bonded to the contiguousnon-elastomer cylindrical bearing shells.
 4. The cylindrical laminatedbearing material as defined in claim 1 wherein the non-elastomer flatband is a metal band.
 5. The cylindrical laminated bearing material asdefined in claim 4 wherein the metal band is a brass-plated steel shimstock having a thickness from 0.020 to 0.0015 inches.
 6. The cylindricallaminated bearing material as defined in claim 4 wherein the elastomeris a rubber compounded for the desired characteristics.
 7. Thecylindrical laminated bearing material as defined in claim 5 whereineach elastomer cylindrical bearing shell has a wall thickness from 0.005to 0.060 inches.
 8. The cylindrical laminated bearing material asdefined in claim 2 wherein each elastomer cylindrical bearing shell isapplied in an uncured state and is cured and bonded to its contiguousnon-elastomer cylindrical bearing shells.
 9. The cylindrical laminatedbearing material as defined in claim 2 wherein the non-elastomer band ineach successive non-elastomer cylindrical bearing shell is disposed atan angle to the non-elastomer band in the immediately precedingnon-elastomer cylindrical bearing shell whereby substantially uniformbi-directional torsional response is obtained.
 10. The cylindricallaminated bearing material as defined in claim 9 wherein thenon-elastomer bands in adjacent non-elastomer cylindrical bearing shellsare helically disposed at equal but opposite angles with reference tothe axis of the cylindrical laminate.
 11. A laminated bearing for radialand limited torsional loadings comprising a core having a cylindricalouter surface, and a plurality of concentric elastomer and metalliccylindrical bearing shells successively superimposed on said core toform a cylindrical layered laminate thereon, each metallic cylindricalbearing shell formed by a metal band helically disposed in anedge-abutting relationship to form a metallic cylinder with a helicalseam which has a substantially constant diameter.
 12. The bearing asdefined in claim 11 wherein the bearing includes an outer cylindricalretaining member which is contiguously disposed on the outermostcylindrical bearing shell of the cylindrical laminate.
 13. The bearingas defined in claim 11 wherein the adjacent metallic cylindrical bearingshells forming the cylindrical laminate are separated by elastomercylindrical bearing shells.
 14. The bearing as defined in claim 12wherein the plurality of concentric elastomer and metallic cylindricalbearing shells are compressed between the outer retaining member and theouter cylindrical surface of the core to decrease its radial deflectionin the resulting bearing.
 15. The bearing as defined in claim 12 whereinthe outer retaining member is segmented with gaps between the ends ofits segments whereby the cylindrical laminate between the core and saidouter retaining member can be compressed by closing such gaps when thebearing is installed in cooperating structures to decrease radialdeflection in the installed bearing.
 16. The bearing as defined in claim13 wherein the elastomer cylindrical shells are cured and bonded totheir contiguous metallic cylindrical bearing shells.
 17. The bearing asdefined in claim 11 wherein the metal bands forming the metalliccylindrical bearing shells are cold-worked to induce a curl in saidmetal bands approximately the diameter of the cylindrical laminate whenthey are wound.